Revolvers having a swing-out cylinder have withstood the test of time because they permit ease of loading and ejecting cartridges without compromising the strength of the frame. Such revolvers present special design challenges, in particular, challenges concerning the use of detent mechanisms to maintain the revolver in a closed configuration. The mechanism must be robust and reliable; it must maintain the revolver closed during firing yet allow it to be readily opened manually for ejecting spent cartridges and reloading. It is also advantageous if the detent mechanism helps to maintain precise alignment between cylinder and barrel. Ideally, the detent mechanism would be simple to make and assemble on the revolver frame.